This study will focus on three groups of schoolboys (7-9 year olds): 20 normal achievers, 20 learning disabled but not hyperactive, and 20 hyperactive but not academically retarded. The hypothesis is that a learning disability per se stems for temporal lobe dysfunctioning whereas hyperactive disruptive behavior stems from frontal lobe dysfunctioning. The principal procedure, a problem solving task involving visual field displays building up from 2 to 12 choices, follows one developed by Karl H. Pribram, who found that temporally lesioned monkeys tended toward excessive repetitive search errors but that frontally lesioned monkeys made more after search errors. The former failer to sample options widely enough and the latter failed to benefit from positive feedback once they found the rewarded symbol. To explore further the suggested parallel in the problem solving approach of Pribram's monkeys and the above two groups of MBD children, we are assessing temperament, Locus-of-Control, role-taking ability, and moral development. The hyperactive boys are hypothesized to tend toward extraversion and externality and to be at a lower stage of moral development than the other two groups. Autonomic and electroencephalographic recordings are expected to show that both groups of MBD children are less responsive to significant stimuli than normal achievers. BIBLIOGRAPHIC REFERENCES: Dykman, R.A. and Ackerman, P.T. An information processing model of minimal brain dysfunction. In D.V.S. Sankar (Ed.) Psychiatric and psychological problems of childhood. New York: P.J.D. Publications, 1975. Dykman, R.A. and Ackerman, P.T. The MBD problem: Attention, intention and information processing. In R.P. Anderson and C.G. Holcomb (Eds.) Learning disability - minimal brain dysfunction: Research perspectives and applications. Springfield, Ill: Thomas, 1975.